Effect of microfracture and autologous-conditioned plasma application in the focal full-thickness chondral defect of the knee: an experimental study on rabbits

PURPOSE The aim of the present study was to evaluate the effect of microfracture and intraarticular autologous conditioned plasma (ACP) injection on cartilage regeneration in a focal full-thickness chondral defect model created in the knee joint. METHODS Full-thickness chondral defects of 3 × 6 mm(2) were surgically created in right medial femoral condyles (MFC) of New Zealand rabbits, and the rabbits were then divided into three groups according to treatment: Group 1 received only microfracture (mfx), Group 2 received mfx plus intraarticular ACP, and Group 3 received mfx; the defect was covered by the periosteum, and then, ACP was applied subperiosteally and intraarticularly. Twelve weeks after injection, the animals were sacrificed and the femoral condyles were evaluated macroscopically and histologically by hematoxylin-eosin staining. Then, histological sections were scored using the International Cartilage Repair Society (ICRS) visual histological scale. RESULTS Findings showed that in both mfx/ACP-treated groups, the defects were filled regularly and smoothly, the defects had a greater fill and good integration into the surrounding host tissue, and the repair matrix had more hyaline-like character. On the other hand, defects were filled with an irregular, fibrous cartilage in the mfx-treated group. Histological scores in Group 2 and Group 3 were better compared to Group 1. CONCLUSION In the present study, we were able to demonstrate a beneficial effect of intraarticular administration of ACP as a coadjuvant of microfractures in order to regenerate hyaline-like cartilage in full-thickness chondral lesions in a rabbit model.